An International Guide to
Patent Case Management for Judges

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7.6.6 Infringement determination Explanatory session

The court will usually not hear parties or witnesses in patent infringement lawsuit proceedings. Rather, the court determines the scope of the patented invention and patent infringement using documentary evidence, such as patent specifications, technical documents of prior art and specifications of the allegedly infringing products. It is also rare for an expert witness to be used to prove the technical background of a patented invention.

However, as the last substantive step of the stage for assessing infringement, the court will usually preside over an explanatory session (technical briefing session).260 These sessions are held not only for cases involving cutting-edge technology or highly specialized technology but also to establish the general understanding of persons having ordinary skill in the art in the technical field in question, or where general technical knowledge in the art is at issue.

Explanatory sessions may take various forms. For example, an explanatory session may be conducted as an official oral court hearing or as part of the preparatory proceedings. An explanatory session conducted as an oral court hearing will be attended by the judges, the judicial research official in charge of the case, a court clerk and three technical advisors selected from among the experts in the technical field in question.261

At the beginning of the session, each party will make a presentation lasting approximately 30 minutes summarizing their arguments and covering technical matters, such as the details of the invention, prior art and common general technical knowledge available at the time when the application was filed. The parties may provide an explanation by using the products produced by working a patented invention and the allegedly infringing products and may use diagrams, presentation software or videos to indicate correlations between the patented invention and the allegedly infringing product.

After the presentation, the participants engage in a discussion that allows both parties, the technical advisors, judges and the judicial research official to ask questions about the content of the presentation or to clarify points in the arguments or evidence. The technical advisors may also present explanations about technical matters. These sessions allow all participants to identify issues and deepen their understanding of technical matters. Preliminary view and settlement

Following the explanatory session, the court will prepare a preliminary view on infringement, taking into account the arguments and evidence, including the technical explanations given by the parties.

If the court finds non-infringement, the court closes the proceedings and delivers a judgment. In some cases, the court may recommend the parties compromise and designate a date for settlement. There are a number of reasons why the court may still recommend settlement in these circumstances, including that the case is not strong and the successful party is not sure if they will be successful in IP High Court proceedings, or that the settlement agreement includes a licensing clause.

If the court finds infringement, the court will express its preliminary view, then proceed to the stage for assessing damages. In some cases, the court may recommend the parties settle at this stage and designate a date for settlement. The court expresses this view on the premise that both parties have completed their arguments and the introduction of evidence regarding infringement.

A large number of cases resolved through court settlement tend to favor the patent holder, including cases where a large amount of damages is claimed.262 In Japan, court settlement is widely recognized as an efficient and speedy way to reach an appropriate resolution.